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Color-tunable dual-mode organic afterglow excited by ultraviolet (UV) and white light was achieved from classical aggregation-caused quenching compounds for the first time. Specifically, two luminescent systems, which could produce significant organic afterglow composed of persistent thermally activated delayed fluorescence and ultralong organic phosphorescence at ambient conditions, were constructed by doping fluorescein sodium and calcein sodium into aluminum sulfate. Their lifetimes surpassed 600 ms, and the dopant concentrations were as low as 5[[EQUATION]]10-6wt%. Moreover, the persistent luminescence colors of the materials could be tuned from blue to green and then to yellow by simply varying the concentrations of guest compounds or the temperature in the range of 260~340 K. Inspired by these exciting results, the afterglow materials were used for UV- and white-light-manipulated anti-counterfeiting and preparation of elastomers with different colors of persistent luminescence.

In this work, an efficient polymer-based organic afterglow system, which shows reversible photochromism, switchable ultralong organic phosphorescence (UOP), and prominent water and chemical resistance simultaneously, has been developed for the first time. By doping phenoxazine (PXZ) and 10-ethyl-10H-phenoxazine (PXZEt) into epoxy polymers, the resulting PXZ@EP-0.25% and PXZEt@EP-0.25% films show unique photoactivated UOP properties, with phosphorescence quantum yields and lifetimes up to 10.8% and 845 ms, respectively. It is found that the steady-state luminescence and UOP of PXZ@EP-0.25% are switchable by light irradiation and thermal annealing. Moreover, the doped films can still produce conspicuous UOP after soaking in water, strong acid and base, and organic solvents for more than two weeks, exhibiting outstanding water and chemical resistance. Inspired by these exciting results, the PXZ@EP-0.25% has been successfully exploited as an erasable transparent film for light printing.

Ultralong organic phosphorescence (UOP) has attracted increasing attention due to its potential applications in optoelectronics, bioelectronics, and security protection. However, achieving UOP with high quantum efficiency (QE) over 20 % is still full of challenges due to intersystem crossing (ISC) and fast non-radiative transitions in organic molecules. Here, we present a novel strategy to enhance the QE of UOP materials by modulating intramolecular halogen bonding via structural isomerism. The QE of CzS2Br reaches up to 52.10 %, which is the highest afterglow efficiency reported so far. The crucial reason for the extraordinary QE is intramolecular halogen bonding, which can not only effectively enhance ISC by promoting spin-orbit coupling, but also greatly confine motions of excited molecules to restrict non-radiative pathways. This work provides a reasonable strategy to develop highly efficient UOP materials for practical applications.

Interfaces play an important role in enhancing the energy conversion performance of dye-sensitized solar cells (DSCs). The interface effects have been studied by many techniques, but most of the studies only focused on one part of a DSC, rather than on a complete solar cell. Hence, monitoring the interface evolution of a DSC is still very challenging. Here, in situ/operando resonance Raman (RR) spectroscopic analyses were carried out to monitor the dynamics of the photovoltaic conversion processes in a DSC. We observed the creation of new species (i.e., polyiodide and iodine aggregates) in the photosensitization process. We also obtained molecular-scale dynamic evidence that the bands from the C=C and C=N bonds of 2,2'-bipyridyl (bpy), the S=C=N bonds of the NCS ligand, and photochemical products undergo reasonably strong intensity and frequency changes, which clearly demonstrates that they are involved in charge separation. Furthermore, RR spectroscopy can also be used to quickly evaluate the performance of DSCs.

Several SQUAMASA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors are involved in plant developmental transition from vegetative to reproductive growth. However, the function of SPL10 in regulating floral transition is largely unknown. It is also not known which Mediator subunit mediates SPL10 transcriptional activity. Here, we used overexpression lines and knockout mutants to examine the role of SPL10 in flowering-time regulation and we investigated possible interactions of SPL10 with several mediator subunits in vitro and in vivo. Plants overexpressing SPL10 showed precocious flowering, whereas the triple loss-of-function mutants of SPL10 and its two homologous genes, SPL2 and SPL11, flowered late compared with wild-type plants. We found that SPL10 interacts with MED25, a subunit of the Mediator complex, which bridges transcription factors and RNA polymerase II to facilitate transcription initiation. Genetic analysis showed that MED25 acts downstream of SPL10 to execute SPL10-regulated floral transition. Furthermore, SPL10 was required for MED25 association with the promoters of two target genes, FUL and LFY. We provide evidence that SPL10 recruits MED25 to the promoters of target genes to regulate flowering time. Our results on the SPL10/MED25 module are relevant to the molecular mechanism of other SPL family members.

Geophysical research letters 48(8), e2021GL092514 (2021). doi:10.1029/2021GL092514, Knowledge of the elasticity of high-pressure ice is key to constructing the internal structure of various planetary bodies. Here, we present direct experimental constraints on the single-crystal elasticity of ice with 0.5 mol/L (0.9 mol.%) NaCl up to 98 GPa at 300 K. The change from ice-VII to the dynamically disordered ice-VII is characterized by an obvious softening of the longitudinal and bulk moduli between 42.4 and 54 GPa. Further transition to ice X at ���64 GPa results in an apparent change in the pressure dependence for the elasticity. Using the obtained elasticity, our modeling reveals that the boundary between the ice-VII layer and the silicate mantle or core in moderate-size icy planetary bodies would be associated with a sudden velocity jump. In large planetary bodies, the change from ice X to the silicate layer will be characterized by an abrupt reduction in velocity., Published by Wiley, Hoboken, NJ

Persistent luminescence from purely organic materials is basically triggered by light and electricity, which largely confines its practical applications. A purely organic AIEgen exhibits not only persistent photoluminescence, but also transient and persistent room-temperature mechanoluminescence. By simply turning on and off a UV lamp, tricolor emission switching between blue, white, and yellow was achieved. The data from single-crystal structure analysis and theoretical calculation suggest that mechanism of the observed persistent mechanoluminescence (pML) is correlated with the strong spin-orbit coupling of the bromine atom, as well as the formation of H-aggregates and restriction of intramolecular motions in noncentrosymmetric crystal structure. These results outline a fundamental principle for the development of new pML materials, providing an important step forward in expanding the application scope of persistent luminescence.

Persistent room-temperature phosphorescence (RTP) in pure organic materials has attracted great attention because of their unique optical properties. The design of organic materials with bright red persistent RTP remains challenging. Herein, we report a new design strategy for realizing high brightness and long lifetime of red-emissive RTP molecules, which is based on introducing an alkoxy spacer between the hybrid units in the molecule. The spacer offers easy Br-H bond formation during crystallization, which also facilitates intermolecular electron coupling to favor persistent RTP. As the majority of RTP compounds have to be confined in a rigid environment to quench nonradiative relaxation pathways for bright phosphorescence emission, nanocrystallization is used to not only rigidify the molecules but also offer the desirable size and water-dispersity for biomedical applications.

Although persistent room‐temperature phosphorescence (RTP) emission has been observed for a few pure crystalline organic molecules, there is no consistent mechanism and no universal design strategy for organic persistent RTP (pRTP) materials. A new mechanism for pRTP is presented, based on combining the advantages of different excited‐state configurations in coupled intermolecular units, which may be applicable to a wide range of organic molecules. By following this mechanism, we have developed a successful design strategy to obtain bright pRTP by utilizing a heavy halogen atom to further increase the intersystem crossing rate of the coupled units. RTP with a remarkably long lifetime of 0.28 s and a very high quantum efficiency of 5 % was thus obtained under ambient conditions. This strategy represents an important step in the understanding of organic pRTP emission.

This study reveals the mechanism of the dual-emission properties for asymmetrical diphenylsulfone and diphenylketone derivatives. A series of asymmetrical diphenylketone and diphenylsulfone derivatives with dual-emission properties are designed and synthesized. By single crystal structure analyses, various photophysical studies, and 2D 1H–1H NOSEY NMR studies, the lower energy emission bands in the dual-emission spectra are successfully assigned to hydrogen-bonding-assisted intermolecular charge transfer emission. The emission properties of these compounds can easily be tuned in both solid state and solution state by destroying or strengthening the intermolecular hydrogen bonding. In addition, thermally activated delayed fluorescence characteristics for the intermolecular charge transfer emissions are also observed. The control of the intermolecular and intramolecular charge transfers serves as the basis for the generation of the white-light emission. For compound CPzPO, nearly pure white-light emission with CIE coordinates of (0.31, 0.32) is easily achieved by precipitation from dichloromethane and hexane mixed solvent system. These results clearly give an insight into the dual-emission properties and provide a rational strategy for the design and synthesis of single-component white-light-emitting materials and mechanoresponsive light-emitting materials.

A variety of aldoximes and ketoximes were oxidized to corresponding aldehydes and ketones by nitric oxide in the presence of oxygen. A presumed mechanism was suggested.